PicoDrive potentially marking polling frames as non-polling

[YoshiRulz]

Initially reported by Tuffcracker on Discord.

so in knuckles chaotix, i've been working on special stages for the best ending, and i've noticed that some frames are not being considered "lag frames," they're labelled green in TAStudio but the game doesn't register any inputs on that frame, is that just a picodrive issue? it's also kind of the same vice versa where a frame that's red in TAStudio does actually register a button input on that frame (most noticable in speed slider in my any% tas)
[...]
i actually have a couple examples in the improved movie i submitted a bit ago, there's a spot on frame #74772 where i press up to throw mighty up and right, and the game registers that i pressed up on the frame
[Knuckles' Chaotix any imp.bk2]
frame #87017 has the same thing, where i press up and the game registers that
frame #87249 has a similar thing, but the game also registers that i hit A to deduct 10 rings from my counter
frame #96980 has the same thing except i'm throwing him downwards
i'm able to jump on those frames as well, i don't know if it means anything that they're all in speed slider and maybe there's something with the zone itself? as far as i remember i don't think i encountered anything like this in the other zones as well

[vadosnaprimer]

I wonder what gens does.

[CasualPokePlayer]

This seems to be just a weird case of the core internally delaying inputs by a frame effectively. So it's not so much that input on X frame did something on X frame, but rather input on X frame did something on X+1 frame (and X+1 frame is what gets marked as non-lag).